From ea9d7bb798900096f26c585957d6ad9c532417e6 Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Fri, 9 Mar 2018 13:17:01 +0300 Subject: [PATCH] thunderbolt: Prevent crash when ICM firmware is not running On Lenovo ThinkPad Yoga 370 (and possibly some other Lenovo models as well) the Thunderbolt host controller sometimes comes up in such way that the ICM firmware is not running properly. This is most likely an issue in BIOS/firmware but as side-effect driver crashes the kernel due to NULL pointer dereference: BUG: unable to handle kernel NULL pointer dereference at 0000000000000980 IP: pci_write_config_dword+0x5/0x20 Call Trace: pcie2cio_write+0x3b/0x70 [thunderbolt] icm_driver_ready+0x168/0x260 [thunderbolt] ? tb_ctl_start+0x50/0x70 [thunderbolt] tb_domain_add+0x73/0xf0 [thunderbolt] nhi_probe+0x182/0x300 [thunderbolt] local_pci_probe+0x42/0xa0 ? pci_match_device+0xd9/0x100 pci_device_probe+0x146/0x1b0 driver_probe_device+0x315/0x480 ... Instead of crashing update the driver to bail out gracefully if we encounter such situation. Fixes: f67cf491175a ("thunderbolt: Add support for Internal Connection Manager (ICM)") Reported-by: Jordan Glover Signed-off-by: Mika Westerberg Acked-by: Yehezkel Bernat Cc: stable@vger.kernel.org --- drivers/thunderbolt/icm.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/thunderbolt/icm.c b/drivers/thunderbolt/icm.c index 6b1041677604..2d2ceda9aa26 100644 --- a/drivers/thunderbolt/icm.c +++ b/drivers/thunderbolt/icm.c @@ -1452,6 +1452,9 @@ static int icm_firmware_reset(struct tb *tb, struct tb_nhi *nhi) struct icm *icm = tb_priv(tb); u32 val; + if (!icm->upstream_port) + return -ENODEV; + /* Put ARC to wait for CIO reset event to happen */ val = ioread32(nhi->iobase + REG_FW_STS); val |= REG_FW_STS_CIO_RESET_REQ;